Improvement in pavements



Pmmm) MAY 1.71870 10-8 05; v A VAN cAMP AND M. .M.HODGMAN PRESERVINGWOOD FOR PAVEMENTS AND FOR OTHER PURPOSES.

.1 WITNESSES? mmnm;

ANT) V'hu aiiected by frost and moisture' AARON VAN CAMP, or WASHINGTON, DISTRICT or ooLUMnm, Ann

- HODGMAN, or sr. LOUIS, imssoom;

li igimt ances M.

IMPRO EMENT m PAVEMENTS.

The Schedule referred to in these Letters Patent and making pair: cf the 511129.

1'0 all whom it may concern Be it known that we, AAROXVAN CAMP, of Washington City, District of Columbia, and MARCUS M. -HODGMAN, of St. L0uis,-in the countyof St. Louis and State of Missourn'ha-ve, invented certain new and. useful Improvements in the Method of PreservingWo'od'for Pavements, and for other purposes; and we do hereby declare that thefollowing is a full, clear, amlexact description of the same, reference being had to the accompanying drawing and to the letters of reference marked thereon, making part of this specification, in which-- Figure 1' is a side view. Figure 2 is a top view. Figure 3 is a side view of the block, showing-the direction of the cut. e y The nature of our invention consists inso preparing the blocks for a wood pavement that when the same. are laid th'eywill resist moisture and remain entirely unaffected by atmospheric change. The so-. lntion we use for'this purpose is composed of pyroligucous acid, sulphateof iron, and born, or their clear chemical equivalents or production. This. solution we infuse into the blocks, so as to completely fill the pores, by the aid of an exhaust cylinder, as is employed in the Burncttiziug process, or by any like arrangement. v

The nature of our invention also consists in cut; ting the block in such form as to preserve all the advantages incident to-the wedge, retaining the, groove, as shown in our patent of November 16, 1869, and so pouring the concrete or cement down as to furnish a lateral coating for the entire face of the block.

The advantages resulting fiom-this plan of p reparing and laying the blocks will readily suggest themselves toany one familiar with the difficulties incident to the rendering of wood incapable of being Besides the im-v provement in the block, resulting from its impervious nature, it is so sawed outthat there will be a great savingiu material, and also maintain the run of its grain in such manner as most effectively to resist the wear of the animals and vehicles.

To enable others skilled in the art to makeaud use our invention, we will now proceed todescribe its construction and operation. V

' A A represent the blocks which, beforebeinglaid,

are to be so prepared by the composition composed;

of 1.)yroligneous-acid, sulphate of iron, and borax, or theirchemical equivalents, as to insure the filling of.

"jug witnesses.

to moisture.

Of course there are many plans by which the blocks may be treated seas to accomplish the desired result.

An exhaust cylinder and pump may be used, or any other mechanical eqnivalent.-

The direct term of the block is shown in fig. 3. and

it will be observed that it is cut diagonally, in the.

direction of the line a" x, which gives all the advantages of the wedgeshape, and retains the entire strength of the grain.

After the blocks of wood are thus cut,. losing none of the material, the half section A is reversed and placed alongside of the other half section A, clearly shown in fig. 1.

By this means the broad base of the blocks form as it were afloor, while the upper surface has leftsutticieut space between: the blocks for the concrete to enter.

The advanta e resultin from this forni'of block D D is not only that each block is firmly secured to the next by concrete B or cement C, but also that sand and other materials are prevented from being forced up between the recesses during the process of laying the blocks. y

The cross-joints a a are dipped in hot asphaltnm,

which not only renders the pavement impervious to moistureat this point, but also greatly facilitates the process of layin v Having thus fully described our im cution', What we claim therein as new, and desire to secureby Letters Patent of the United States,- is

I 1. So soaking the block in a composition of pyroligneous acid,,snlphate of-iron, and borax, or their clear chemical equivalel'lts' or deductions, -as to produce the-result specified. l g

.2. Constructing a pavement, of blocks A. A, and concrete or cement, when saidbloclrs are grooved, as

shown, and wedge-shaped, one lateral surface being straight and the other angular or inclined, substantially as described.

In testimony whereof we have signed our names to this specification in the presence of two subscrib- A. VAN ,OAMP.

' MUM. HODGMAN.

Witnesses:

V EDWIN J AMES,

FRED. Koon'ns. 

